This invention relates to an electric motor, particularly a commutator motor enclosed in its housing liquid-tight and used for driving an axially flanged-on hydraulic pump.
European Published Patent Application 0 472 746 A1 discloses an electric motor in which an eccentric rotor stub shaft projects externally through the bearing plate (closing an end face of the motor housing) for driving plungers of a flanged-on hydraulic pump. In the bearing plate a separate brush carrier plate is mounted; the brushes cooperate with the commutator in a conventional manner. Because of the numerous individual components, the labor input in assembling such an electric motor is very high.
Furthermore, in German Patent Application P 42 35 962.7 an electric motor is described in which a flat sealing element between the motor and the flanged-on hydraulic pump is constituted by the brush carrier plate. In this construction the electric motor flanged to the housing of the hydraulic pump has no bearing plate which closes the motor housing liquid-tight and which normally carries a roller bearing supporting the rotor shaft. In the construction according to German Application P 42 35 692.7 the sealing function between the motor and the pump housing is assumed by the brush carrier plate. The latter simultaneously serves as a centering element for the roller bearing secured to the motor shaft. Such an arrangement constitutes a first verification for the Electric motor in this phase of assembly. Also, the electric motor can safely be transported in such a preliminarily assembled condition. By the elimination of the bearing plate an inexpensive and easily assemblable electric motor unit is provided for driving a hydraulic pump.